Control means for liquid fuel injection pumps of internal combustion engines



June 11, 1957 2,795,219

F. M. EVANS CONTROL MEANS FOR LIQUID FUEL INJECTION PUMPS OF INTERNAL COMBUSTION ENGINES Filed Feb. 14, 1955 s Sheets-Sheeti J1me 11, 1957 F. M. EVANS 2,795,219 CONTROL MEANS FOR LIQUID FUEL INJECTION PUMPS OF INTERNAL COMBUSTION ENGINES 3 Sheets-Sheet 2 Filed Feb. 14, 1955 FigA F. M. EVANS CONTROL MEANS FOR LI June 11, 1957 QUID FUEL INJECTION PUMPS OF INTERNAL COMB USTION ENGINES 3 Sheets Sheet 3 Filed Feb. 14, 1955 United StatesPatent O TION PUMPS OF INTERNAL COMBUSTION ENGDNES Fraser Mackie Evans, Acton, London, England, assignor to C. A. V. Limited, Acton, London, England Application February 14, 1955, Serial No. 487,950

Claims priority, application Great Britain February 18, 1954 2 Claims. (Cl. 123-140) For supplying liquid fuel to an internal combustion engine, it is customary to employ an injection pump of the reciprocatory plunger type having combined with it a governor for varying the rate of discharge of fuel under different load conditions, the governor consisting in part of a slidable bar. The position of this bar when the normal maximum fuel supply is required or when the engine is at rest, is determined by a stop against which the bar is held by a spring, the bar being moved away from the stop and against the action of the spring for reducing the pump output under normal or light load conditions. When starting the engine it is usually required to obtain from the pump a temporary extra supply of fuel in excess of the normal maximum, and the object of the present invention is to enable the extra supply to be obtained in a simple manner which cannot be abused by the driver.

The invention comprises the combination of a manually operable slidable pull-push rod, a collar formed on or secured to the rod, a stop collar slidable on the rod and situated between the first mentioned collar and one end of an associated spring, the stop collar having a peripheral surface of frustro conical form, and an abutment extending from the slidable control bar of the pump for cooperating with the stop collar, the parts being adapted to co-operate as herein described.

The invention also comprises a modification of the device above defined whereby it can serve the additional purpose of moving the control bar of the pump to its minimum fuel supply position for stopping the engine.

In the accompanying drawings, Figure 1 is a sectional side view and Figure 2 a sectional end view of a mechanism embodying the invention.

Figures 3 and 4 are respectively similar views to Figures l and 2 illustrating the above mentioned modification of the invention.

Figure 5 is a diagrammatic part sectional side view illustrating the form of the invention shown in Figures 1 and 2 applied to a fuel injection pump provided with a speed-responsive governor.

Referring to Figures 1, 2 and 5, there is provided adjacent and at right angles to one end of the slidable control bar a of the pump b, a rod which is slidably supported adjacent to its ends by a part of the housing d of the pump governor. The latter includes a lever e operable by a mechanism 10 (which as shown in Figure is responsive to engine speed, but which may be responsive to other conditions), and a link 1 through which the lever e can impart endwise movements to the bar a. On the outer projecting end of the rod c is provided a finger piece g, and on the portion of the rod within the housing is formed or secured a collar h. Adjacent to one end of this collar there is freely mounted on the rod a slidable stop collar i, the latter being in contact with a spring mounted on the rod which tends to hold the second collar i in contact with the collar h. The periphery of the collar i is of frustro conical form, and by the co-operation with its periphery of an abutment k adjustably secured to an arm m extending rigidly from the control bar a, it serves as a stop for 2,795,219 Patented June 11', 1957 7 ice determining the normal maximum fuel supply position of the control-bar. The position of the stop collar i relatively to the abutment k may be adjusted by a bush n which is in screw thread connection with the housing and which abuts against one end of the collar h secured to the rod.

The pump and its governor are of well known form, and no further description thereof is necessary to elucidate the invention.

The arrangement is such that when the engine is at rest and an extra quantity of fuel is required for starting, the driver first pushes the rod 0 inwardly against the action of the spring 1'. The effect of this is to cause the stop collar i to slide past the abutment k, and when the larger end of this collar has passed the abutment, the latter moves inwardly under spring action exerted on the control bar a by, for example, the springs as 11 forming components of the governor mechanism 10. In this condition the abutment engages the end face of the larger end of the stop collar to an extent which at first is determined by the fixed collar 11, the latter being of about the same diameter as the smaller end of the stop collar. The driver then pulls the rod 0 back to its initial position and this enables the abutment k (under the aforesaid spring action on the control bar a) to move between the two collars h, i and so allow the control bar a to be moved by its spring to the extra-fuel supply position. When the engine is in motion and has attained a sufficient speed to bring the governing means into action, the control bar moves the abutment k away from the stop collar and so allows this collar to be moved by its spring j to its initial position in contact with the collar h. So long as the engine is running, any further actuation of the slidable rod c by the driver will fail to have any effect and consequently any attempt which the driver may make to obtain extra fuel otherwise than when starting is effectively frustrated.

It will be understood that the normal maximum supply is determined by contact of the abutment k with the conical periphery of the stop collar i, and this amount can be adjusted by adjustment of the bush n.

In the modified form of the device shown in Figures 3 and 4, the slidable rod c is adapted to be movable angularly about its axis as well as axially. For example it is provided with a lever g On the collar h which is formed on or secured to this rod is provided a radial arm 0 arranged to abut against a lateral projection p on the pump control bar a, so that by angular movement of the rod c the control bar can be moved to the minimum fuel supply position for stopping the engine. In this example the spring j may be a torsion spring adapted to impart both axial and angular movements to the rod 0, or alternatively an additional spring q acting on a second arm r on the collar h may be provided as shown. In other respects the device shown in Figures 3 and 4 is similar to the one described with reference to Figures 1 and 2.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

l. Extra-fuel controlling means for a liquid fuel injection pump provided with a slidable output-control bar, comprising the combination with said control bar, of a manually-operable push-pull rod situated at right angles to said control bar, a housing by which said push-pull rod is supported, and into which said control bar extends, a first collar provided on and rigid with said push-pull rod, 2. second collar slidable on said push-pull rod, a spring acting on said second collar and urging the latter towards said first collar, and an abutment extending laterally from said control bar at a position adjacent to said second collar, the latter having a frusto-conical peripheral surface which serves by contact with said abutment to determine the normal maximum fuel supply position of said control bar, and being movable out of the path of said abutment by said first stop in response to a pushing movement ap1 pliedio said push-pull rod fonpermitting said control bar to move beyond its normal maximum fuel supply position. 1

2. Extra-fuel controlling means according to claim 1, and having in combination a'lateral projection on said control: bar, nand a radial arm- =0n= said- 'push pnlb rodg flie 5 latter being also angularly' movable to cause said armdo 1 821 887 act on said *projection" for moving said I control ban to-a minimum fuel5supply position.

Refcrences Cited in the file of this patent UNITED STATES" PATENT S" 2,474,121 Sanders June 21', 1949 FOREIGN PATENTS France l. Dec. 15, 1937 

